There are some common mistakes made by new airgunners that cause them some real headaches as they first start out. The biggest misconception is that spring / gas ram airguns shoot just like, or take less skill and technique to shoot, than traditional firearms. Nothing could be further from the truth. Not only do spring / gas ram guns take MORE technique and discipline, they require a proper break-in period to burn off excess lubricants and allow all the moving parts to mesh. So many guns are returned because the new owners don’t see immediate accuracy. It just doesn’t work that way.
Taking your first shots…
I’ve mentioned this many times on the blog, the importance for airgunners to own a chronograph. It’s the single most important piece of diagnostic equipment that you can have. It can tell you if your airgun is meeting velocity specification and also help diagnose if there are internal problems without having to actually take the rifle apart.PACT Professional Chronograph
The RWS 34 .177 is a 1000 FPS class airgun with lightweight lead pellets. That means that I should be able to get close to that performance as I take my first shots with the 7.0 grain RWS Hobby pellets. After sending 20 or so preliminary shots down range, I setup my chrony and conducted my initial velocity tests. The results tell me that I’m going to have an extended break-in period with this one as it’s got a lot of factory lubrication that it needs to burn off.RWS Hobby Pellets .177 cal – 500 ct
Here are my results with the RWS Hobby Pellets:
High: 1067.7 FPS
Low: 1005.5 FPS
Average: 1032.8 FPS
Extreme spread: 61.8 FPS (ideally you’d want it to be 20 FPS or less)
Standard Deviation: 19.5 FPS
These are not the numbers of a gun that’s ready to be shot for accuracy. So what do we do now?
Getting it to calm down…
First of all, this is pretty typical. But, imagine if you didn’t know that the gun was still all over the place regarding velocity and you tried to mount a scope and sight it in at 25 yards? You’d be VERY frustrated as a 19.5 FPS standard deviation would cause your point of impact to never hit the same place twice. This gun is just not ready for sighting-in yet. What we need to do is continue to burn off that excess factory lubrication. At this point, knowing that I’m shooting well over the factory specifications, I’ll switch to some much heavier pellets. A heavier pellet can sometimes calm down the dieseling effect and help you get through the break-in period more quickly.H&N Baracuda Match, .177 Cal, 10.65 Grains, Round Nose 500ct
After switching to the H&N Baracuda Match pellets at 10.61 grains, my new gun is still dieseling quite a bit. So I’m going to need to spend more time simply getting the gun to settle down.
What is “dieseling?”
For those of you who are new to spring / gas ram airguns, dieseling is when the pressure from the piston causes so much heat that the residual lubricants hit a flash point and ignite in the compression tube. Back in my early days of airgunning, and not knowing any better, my buddy and I would spray gun oil into the transfer port thinking we were helping “lubricate” the gun. It always made the next couple of shots pretty exciting as it made our airguns sound like a .22 LR. However, I now know that doing so was damaging our guns and was also very dangerous. This is one of those “don’t do what you see on-line” type of things. I was introducing a combustible material, i.e. gun oil, into a compression chamber which was compressed under great force by the “piston,” causing detonation. This is the same principle that a diesel engine operates on and where we get the term dieseling. While it will make your airgun shoot faster for a few shots, and make it sound very “impressive,” it will also damage your main seal and greatly reduce the life of your gun. In most cases, it will also void your warranty.
Back to the RWS 34
So my new RWS 34 is still pretty “juicy” and is going to need a lot more break-in time. So, I’m going to go get on the bench and start putting pellets through it until it settles down. Hopefully I’ll get through that process and be able to hit Part 3 which will be basic accuracy testing and some tips on finding the right pellet. Keep an eye on the blog for part 3!